Scenic with low power

Hi guys, my scenic 1.5dci mk 2 2005 is low on power especially on hills, garage had this two weeks ago and said they had just pushed pipes back but would not confirm which ones and it seemed ok until now, took it back to garage and was told all pipes are ok but reads fault codes DF427 turbo actuator control and DF089 inlet pressure monitor, changed MAP sensor for DF089 and idle speed seems to be smoother and was advised to replace boost pressure solenoid 8200575400 and now waiting for delivery and hope that it brings turbo back in , have you any further advise please as im a retired car mechanic and im nearly 70 years of age and too old to be climbing under cars for too long.

Thanks guys

Pete